Sleep inertia
1130302
222154354
2008-06-27T20:37:53Z
Hordaland
4755260
Removed 2 categories, nonsense added by 24.96.172.194.
'''Sleep inertia''' is a physiological state characterised by a decline in motor [[dexterity]] and a subjective feeling of grogginess, immediately following an abrupt [[awake|awakening]]. Sleep inertia can also refer to the tendency of a person to want to return to [[sleep]]ing, even after suitable rest has been achieved. Typically, sleep inertia lasts up to 3 hours for a night wake up and up to 90 minutes for a day wake up. If the subject is awakened due to a perceived danger, however, the duration of sleep inertia is reduced to only a few seconds.
==Factors==
[[NASA]] studies have shown that a variety of factors influence the severity and duration of sleep inertia. These include:
* Depth of sleep when woken. After roughly 30 minutes, the body enters into [[deep sleep]]. More sleep inertia than otherwise occurs when awakening from deep sleep, that is, stages 3 and 4 of [[Non-rapid eye movement sleep|NREM]].
* Time of sleep. Sleep inertia is thought to be related to the phase of the body's [[circadian rhythm]]. Waking during a trough in [[body temperature]] tends to produce more sleep inertia.
* Chemical influences. Studies have shown that drugs such as [[caffeine]] suppress the effect of sleep inertia, possibly by blocking [[adenosine]] receptors in the [[brain]].
According to Patrick Sherry, who specializes in rail safety, sleep inertia can be more severe and last longer when a nap follows a prolonged period of wakefulness or an accumulated sleep debt. Sleep inertia can often be reversed by activity and noise as well as caffeine. Reaction time performance is directly related to sleep stage at awakening; persons awakened during stage 4 sleep (the deepest) yield maximum reaction times.<ref>{{cite web
|url= http://mysite.du.edu/~psherry/fatigue/sleep.html |title= The Science of Sleep and Fatigue |accessdate= 2008-06-01 |last= Sherry |first= Patrick |year= 1999 |month= March |format= |work= monograph |publisher= University of Denver |pages= |quote= }}</ref>
==Cause==
One theory is that sleep inertia is caused by the build-up of [[adenosine]] in the brain during [[non-REM sleep]]. [[Adenosine]] then binds to receptors, which produce the feelings of tiredness.
== References ==
{{reflist}}
==See also==
* [[Circadian rhythm sleep disorder]]
* [[Delayed sleep phase syndrome]]
==External links==
*[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11683484&dopt=Abstract Abstract: Caffeine eliminates psychomotor vigilance deficits from sleep inertia]
*[http://www.findarticles.com/p/articles/mi_m0IBT/is_10_58/ai_92949462 Flying Safely Article on Napping]
{{SleepSeries2}}
[[Category:Sleep]]
[[Category:Sleep physiology]]
[[Category:Circadian rhythms]]